UEFA are only producing the Euro 2024 games in 1080p HDR. Same as they did for the Champions, Europa, and Conference League finals this year to save a few pennies.
BBC iPlayer shows the games in HDR. And I must admit, the picture quality on them is pretty impressive, much better than the garbage they're sending through the terrestrial or satellite broadcasts. However, they do have a delay of around 45-50 seconds compared to their linear broadcasts. If you can live with the delay, its worth watching on iPlayer if you have a pretty decent TV.
From what I have read, Rai 4K show an upscaled feed. I have not seen it, so cannot comment on how good the quality is, or if it is in HDR.
Lyngsat also shows the BEIN MENA 4K channel showing the games - again, not sure how good the quality is.